Short answers, pulled from the story.
The Saturn family was developed by a team led by Wernher von Braun and other former Peenemunde employees at the Army Ballistic Missile Agency. Von Braun proposed the Saturn name in October 1958 as a logical successor to the Jupiter series.
A total of 24 humans were carried to the Moon by Saturn V rockets over the four years spanning December 1968 through December 1972. Saturn V flew 13 times in total, also launching the Skylab space station on the 14th of May 1973.
The cluster approach used existing missile hardware and could meet the required schedule and budget. A single large engine of the needed size had never been built, and development would have taken until the mid-1960s. Switching from four E-1 engines to eight H-1 engines was estimated to save as much as $60 million and up to two years of development time.
The three flown versions were the medium-lift Saturn I, which flew ten times; the heavy-lift Saturn IB, which flew nine times; and the super heavy-lift Saturn V, which flew 13 times. The Saturn IB's final flight was on the 15th of July 1975 for the Apollo-Soyuz Test Project.
No Saturn rocket failed catastrophically in flight. The one catastrophic exception occurred on the launch pad during the Apollo 1 test, when a fire ignited in the crew module and killed all of the astronauts on board.
Saturn V was selected primarily because it required only one new factory, for the largest lower stage, while the rival Nova design would have needed entirely new factories for all of its major stages. The selection of the lunar orbit rendezvous mission profile also reduced launch weight requirements to within the Saturn V's range.